1. Technical Field
The invention relates generally to a network switch for communications networks, and more particularly to a redundant network switch which is able to interface with and segregate two or more independent Ethernet networks. A method of using the redundant network switch interface device is also presented.
2. Related Art
It is often desirable to form multiple connections to devices on an Ethernet network to enhance reliability, or to connect one or more Ethernet device(s) to two independent networks. The vast majority of Ethernet devices have only a single Ethernet port, and/or either limited or no capabilities to make multiple, independent connections.
Local Ethernet devices are commonly connected to an Ethernet network by use of a device known as an Ethernet hub or network switch. These devices typically make the required connections with no regard to segregation or restriction of network traffic. There are significant limitations to the usefulness of using these network switches to make connection to independent networks. These limitations include, inter alia:
a) Unmanaged network switches pass messages from one network to the other, thus removing independence of the networks. This unwanted traffic increases network loading; can breach security through the undesirable transmission of messages; and can cause network conflicts if, for example, duplicate addressing is in use on the independent networks.
b) In the case of applications utilizing redundant network paths, unmanaged network switches could send messages back to network nodes that have received this message already from another path. This undesired event could cause unacceptable confusion on the network.
c) In redundant network schemes it is desirable to know when a failure in one of the network paths occurs so that a repair can be made. Network switches do not identify the path of the message for this purpose.
d) While many of these limitations can be overcome with a managed network switch or router, these complex devices require configuration and careful network planning. Further, the addition of new devices on the network or changes in the network topology can require reconfiguration for continued operation.
Accordingly, there exists a need for a simplified redundant network interface, which is capable of solving the above-mentioned limitations related to network switches for making connections to, as well as to providing segregation and redundancy for, independent networks.